Nothing but the Facts About Earth

1) Position in the solar system: 3rd planet from the sun

2) Closest distance to the sun: Perihelion: 1.471x10^8 km, 9.14x10^7 miles

3) Farthest distance from the sun: Aphelion: 1.521x10^8 km, 9.45x10^7 miles

4) Earth day: 23hr 56m 4.09s

5) Earth year: 365.24 days

6) Axis tilt: 23.439 degrees

7) Orbital Inclination to ecliptic: 0.00005 degrees

8) Orbital Eccentricity: 0.01671

9) Diameter (equatorial): 12,756.28 km, 7926.38 miles

10) Mass: 5.9737x10^24 kg, 1.317x10^25 lbs

11) Gravity: 9.766 m/s2, 32.041 ft/s2

12) Escape Velocity: 11.186 km/s, 6.951 miles/s

13) Temperature range: -88 to 58C, -126 to 136F

14) Wind speed range: 0 to 360 km/hr, 0 to 223.69 miles/hr

15) Mean Surface pressure: 1.013 bars, 1atm

16) Atmospheric Composition: 78.084% nitrogen, 20.946% oxygen, 0.934% argon, 0.038% carbon dioxide, varying amounts of water vapor.

17) Total mass of atmosphere: 5.1x10^18 kg, 1.12x10^19 lbs

18) Total mass of hydrosphere: 1.4x10^21 kg, 3.09x10^21 lbs

19) Number of moons: One

20) Ringed system? No

21) Magnetic Field? Yes

At left: The Earth, as viewed from the moon. (Image credit: http://commons.wikimedia.org/wiki/Image:Earth-moon.jpg)

At right: A depiction of how seasons change as the Earth revolves around the sun. (Image credit: http://commons.wikimedia.org/wiki/Image:North_season.jpg)

1) Researchers recently modeled the inner-most part of Earth's core for the first time. The inner core, which is solid and made mostly of iron, plays a key role in generating our planet's magnetic field and transmits seismic waves at different speeds, depending on the direction in which waves are traveling. "“For many years, we have been like blind men touching different parts of an elephant,” said Xiaodong Song, a geologist at the University of Illinois. “Now, for the fist time, we have a sense of the entire elephant, and see what the inner core of Earth really looks like.”

2) While the emergence of life first helped alter the Earth's atmosphere by taking up carbon dioxide and emitting oxygen, humanity's impact on the planet has become so great that scientists have declared we are no longer living in the Holocene, but in a new, man-made epoch: the Anthropocene.

3) Plate tectonics, the process that shapes and reshapes the Earth's crust, might not be as continuous as scientists once believed. Recent research indicates that plate tectonics might have shut down at least once a billion years ago, and could do so again one day far in the future.

http://sse.jpl.nasa.gov/planets/profile.cfm?Object=Earth&Display=Facts

http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html

http://www.daviddarling.info/encyclopedia/E/Earth.html

http://www.eurekalert.org/pub_releases/2008-03/uoia-rcd031008.php

http://www2.le.ac.uk/ebulletin/news/press-releases/2000-2009/2008/01/nparticle.2008-01-25.1681228573

http://www.whoi.edu/page.do?pid=9779&tid=282&cid=35767&ct=162